Maths... they do still teach it in schools, right?

I'm on facebook, checking how many awesome friends I have when I see this:
6  1 x 0 + 2 / 2
ANSWER IT
"Challenge Accepted" I think to myself. I do mention that it depends on the order of precedence  but the correct answer taking that into account is 5.
Several thousand people have answered, some of them citing the above 'rules'  but a lot of people are coming to a conclusion of 7
SEVEN....?
I asked how anyone had got to 7 and some guy came out with some bullshit about the subtract sign inverting the 1 making it 6 + ((1 x 0) + (2 / 2))... how exactly the fuck does that work?
Do I need to go on a bell tower climbing killing spree with a sniper rifle or are people just making this maths shit up on the fly? Tomorrow I expect to walk into a shop, spend £9.35, give the cashier £10 and get 7p change because they just decided to add some their own bullshit rules or maybe they are just counting in base 11.5...
Then I realise its 7

The minus sign doesn't matter. 6 + 0 is the same as 6  0.

BEDMAS:
 Brackets
 Exponents
 Division, Multiplication
 Addition, Subtraction
= 6  1 x 0 + 2 / 2
= 6  (1 x 0) + (2 / 2)
= 6  (0) + (1)
= 6 + 1
= 7
Where did 5 come from?

Well, I ended up doing it right to left and forgetting about the minus/plus precedence  then I headdesked.

@Charleh said:
or are people just making this maths shit up on the fly?
Only the imaginary numbers.
PADUMTISH

@Charleh said:
I'm on facebook, checking how many awesome friends I have when I see this:
6  1 x 0 + 2 / 2
ANSWER IT
"Challenge Accepted" I think to myself. I do mention that it depends on the order of precedence  but the correct answer taking that into account is 5.
Several thousand people have answered, some of them citing the above 'rules'  but a lot of people are coming to a conclusion of 7
SEVEN....?
I asked how anyone had got to 7 and some guy came out with some bullshit about the subtract sign inverting the 1 making it 6 + ((1 x 0) + (2 / 2))... how exactly the fuck does that work?
Do I need to go on a bell tower climbing killing spree with a sniper rifle or are people just making this maths shit up on the fly? Tomorrow I expect to walk into a shop, spend £9.35, give the cashier £10 and get 7p change because they just decided to add some their own bullshit rules or maybe they are just counting in base 11.5...
Then I realise its 7
*Complains about people not knowing maths.
*Doesn't know maths.

@Master Chief said:
@Charleh said:
I'm on facebook, checking how many awesome friends I have when I see this:
6  1 x 0 + 2 / 2
ANSWER IT
"Challenge Accepted" I think to myself. I do mention that it depends on the order of precedence  but the correct answer taking that into account is 5.
Several thousand people have answered, some of them citing the above 'rules'  but a lot of people are coming to a conclusion of 7
SEVEN....?
I asked how anyone had got to 7 and some guy came out with some bullshit about the subtract sign inverting the 1 making it 6 + ((1 x 0) + (2 / 2))... how exactly the fuck does that work?
Do I need to go on a bell tower climbing killing spree with a sniper rifle or are people just making this maths shit up on the fly? Tomorrow I expect to walk into a shop, spend £9.35, give the cashier £10 and get 7p change because they just decided to add some their own bullshit rules or maybe they are just counting in base 11.5...
Then I realise its 7
*Complains about people not knowing maths.
*Doesn't know maths.

BODMAS, as my maths teacher used to say..
[B]rackets (parantheses, actually, but it sounds better than PODMAS)
[O]f (aka "multiply")
[D]ivision
M]ultiplication
[A]ddition
[S]ubtractionPut into any spreadsheet and that's the answer.

@Quango said:
BODMAS, as my maths teacher used to say..
[B]rackets (parantheses, actually, but it sounds better than PODMAS)
[O]f (aka "multiply")
[D]ivision
M]ultiplication
[A]ddition
[S]ubtractionPut into any spreadsheet and that's the answer.
PEMDAS in these parts. Parentheses, exponents, multiplication/division, addition/subtraction. I swear my sixth grade teacher turned it into a song that we had to sing for a grade.

@Quango said:
BODMAS, as my maths teacher used to say..
Your Maths teacher was somewhat incorrect; or you're misremembering  the O stands for Orders (exponents and roots).
[B]rackets (parantheses, actually, but it sounds better than PODMAS)
[O]f (aka "multiply")
[D]ivision
M]ultiplication
[A]ddition
[S]ubtraction
Put into any spreadsheet and that's the answer.

@Master Chief said:
*Complains about people not knowing maths.
*Doesn't know maths.
THAT is the joke!


Fucking Maths: How do They Work?
Every time I start thinking that the posters to TDWTF or slashdot are freaking boneheads, I just go over and read a couple Facebook or Yahoo threads. Then I realize what true microcraniality is.

Minus is rightassociative, riiiiiiiiight?

Don't feed the trolls. It's deliberately intended to be ambiguous, so you'll comment on it. They are trolling for comments and likes. Accounts with a lot of comments and likes are valuable to advertisers.

@GoatRider said:
Don't feed the trolls. It's deliberately intended to be ambiguous, so you'll comment on it. They are trolling for comments and likes. Accounts with a lot of comments and likes are valuable to advertisers.
What? No it's not, it's perfectly clear.
This one is deliberately ambiguous: a/b(c+d)
Because written as a/b*(c+d) the left to right rule gives this order of evaluation: (a/b)(c+d).
But the ommited multiplication sign creates ambiguity because that's usually only done in situations where you would have this order of evaluation: a/(b(c+d)), the same way as writing it out as a fraction gives you implicit parentheses:a

b*(c+d)

I was just reading the Excel woes sheet  and it kind of crosses with this thread:
Type this into Excel and be angry:
Cell A1: =5
Cell A2: =a1^2+1
Cell A3: =+1a1^2
You can actually find the history behind this !!fun!! with a search, but it's still irritating. I don't know how many spreadsheets have given me funny results because of this "design choice."

@too_many_usernames said:
I was just reading the Excel woes sheet  and it kind of crosses with this thread:
Type this into Excel and be angry:
Cell A1: =5
Cell A2: =a1^2+1
Cell A3: =+1a1^2
You can actually find the history behind this !!fun!! with a search, but it's still irritating. I don't know how many spreadsheets have given me funny results because of this "design choice."
Am I missing something?
a1^2+1 = 5^2+1 = 25 + 1 = 26
+1a1^2 = +1  (5)^2 = +1  25 = 24Which is exactly the result I get from Excel...

@too_many_usernames said:
Cell A1: =5
Cell A2: =a1^2+1
Cell A3: =+1a1^2
A2 has the value of (5) raised to the second power, with one added to the result.
Do you want it to have the value of (5) raised to the third power? If so, you need parentheses!

@joe.edwards said:
The question is on the precedence on the  sign in front of the A1. Either you writeAm I missing something?
a1^2+1 = 5^2+1 = 25 + 1 = 26
+1a1^2 = +1  (5)^2 = +1  25 = 24Which is exactly the result I get from Excel...
or by using the rule that "A1" is exactly the same as "+ ( 1 * A1 ):a1^2+1 = (5)^2+1 = 25 + 1 = 24
+1a1^2 = +1  (5)^2 = +1  25 = 24
The second one, giving 26, seems wrong. Taking the power of 2 of A1 should have precedence over applying the minus signa1^2+1 = (1 * 5)^2+1 = 25 + 1 = 26
+1a1^2 = +1 + (1 * 5)^2 = +1  25 = 26

I think the point is that the minus sign in A2 is being treated differently than in A3. Eg, in A2, it has higher priority than the exponent:
=(a1)^2+1
Instead of
=(a1^2)+1
Whereas in A3, the minus sign is the subtraction operator, and has a lower priority than the exponent. If you rewrite A2 like this, it matches A3:
=0a1^2+1
I guess they added logic to handle minus signs in places where subtraction doesn't make sense, like the beginning of the formula, or this:
=5 + a1

TRWTF is British English. If it's really "maths", it should be "they do still teach THEM in schools, right?"

I guess I see it that  can be a unary operator or a binary operator, and that as a unary operator it yields the additive inverse of the number and has immediate precedence, while as a binary operator it has lesser precedence. In any case, it's acting in line with my expectations. x is evaluated as (1x).

@Charleh said:
Well, I ended up doing it right to left and forgetting about the minus/plus precedence  then I headdesked.
In that case you should get 1, not 5.

@pkmnfrk said:
BEDMAS:
 Brackets
 Exponents
 Division, Multiplication
 Addition, Subtraction
= 6  1 x 0 + 2 / 2
= 6  (1 x 0) + (2 / 2)
= 6  (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
Congratulations. You are the 100,000 person who didn't read the whole story. You have won an Internet!

@TGV said:
Congratulations. You are the 100,000 person who didn't read the whole story. You have won an Internet!
Is that the onehundred thousandth person, or the one hundredth to a precision of one thousandth?
(Yes, this is intentional).

It's the 100'000th person.

@ekolis said:
TRWTF is British English. If it's really "maths", it should be "they do still teach THEM in schools, right?"
And if it's British English, right? should be innit?

@TGV said:
@pkmnfrk said:
BEDMAS:
 Brackets
 Exponents
 Division, Multiplication
 Addition, Subtraction
= 6  1 x 0 + 2 / 2
= 6  (1 x 0) + (2 / 2)
= 6  (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
Congratulations. You are the 100,000 person who didn't read the whole story. You have won an Internet!
I was calling into attention a bit of the story that you clearly did not read:
@Charleh said:
but the correct answer taking that into account is 5.

My guess...
@pkmnfrk said:
I was calling into attention a bit of the story that you clearly did not read:
@Charleh said:
but the correct answer taking that into account is 5.
= 6  1 x 0 + 2 / 2
= 6  (1 x 0) + (2 / 2)
= 6  (0 + 1)

@RTapeLoadingError said:
But clearly wrong, because those two aren't equivalent, since you're introducing a multiplication in the second one.= 6  (1 x 0) + (2 / 2)
= 6  (0 + 1)

@pkmnfrk said:
BEDMAS:
 Brackets
 Exponents
 Division, Multiplication
 Addition, Subtraction
= 6  1 x 0 + 2 / 2
= 6  (1 x 0) + (2 / 2)
= 6  (0) + (1)
= 6 + 1
= 7
Where did 5 come from?
5 comes from inserting an invisible parentheses that don't belong, opening either before the 1 or the 0 and ending at the end of the statement.
Solving in reversepolish notation you get:
6 (push), 1 (push), 0 (push), (multiply), (subtract), 2 (push), 2 (push), (divide), (add)
Each operation either pushes a number onto the stack or performs a binary operation between the 2 most recent numbers on the stack.
A subtract subtracts the current value from the one before it on the stack.
An operation replaces the last 2 numbers on the stack with the value of the current one.
Stack looks like this:
(push 6) 6
(push 1) 6, 1
(push 0) 6, 1, 0
(multiply) 6, 0
(subtract) 6
(push 2 ) 6, 2
(push 2) 6, 2, 2
(divide) 6, 1
(add) 7

Mr CButtius! Will the test be graded on a curve? I did bad on the quiz because my dog was barking and kept me up but I need a C on the test or I won't be able to go to prom!!!
God you people are boring.

I bring worlds together.

There, now I got SOME enjoyment out of this thread.